ES2435413T3 - Non-clogged low pressure discharge hole and elongated screen-grid for a high pressure feeder - Google Patents

Abstract

A rotating high-pressure feeder (70) for processing cellulosic fibrous material, comprising: a rotor with cavities (19) containing a plurality of cavities through which flow passes (21), said rotor (19) being able to rotate around a axis of rotation and said cavities (21) having opposing end openings that function both as inlet and discharge ports according to an angular position of the rotor (19) within the device, and said cavities (21) are provided in at least a first and a second set; a casing (14) enclosing said rotor (19), said casing (14) having a low pressure inlet port (13) aligned with a low pressure discharge port (16), and an inlet port high pressure (15) aligned with a high pressure discharge orifice port (17), in which said ports are arranged to be registered being the inlet orifices to and discharge orifices of said cavities through which flow passes (21) and said rotor (19) mounted in said casing (14) to rotate with respect to said ports about said given axes of rotation, and a screen-grid (72) supported on or adjacent to the low pressure discharge port port ( 16), in which the screen grid (72) has a set of screen slots (84) and bars (82), in which a regular pattern of slots (84) and bars (82) extends through the entire low-pressure discharge orifice port (16), characterized in that a dividing wall (78) passes through the low pressure discharge orifice port (16), and there is a gap (G) between the inner end (76) of the dividing wall (78) and the screen grille (72), in where the liquid flowing through the slots (84) passes through the gap (G).

Description

Non-clogged low pressure discharge hole and elongated screen-grid for a high pressure feeder

Related request

This application requests the benefit of the Provisional Patent Application Serial No. 61 / 169,378, filed on April 15, 2009, the whole of which is incorporated herein by reference.

Background of the invention

The present invention relates to high-pressure feeders (HPF) typically used to pressurize suspension is made of cellulosic material, such as wood chips. The present invention relates in particular to screens that retain cellulosic material in the HPF rotor and allow the liquid to be discharged through a low pressure discharge orifice of the HPF.

High-pressure feeders are typically included in chip feeding systems that supply a suspension of high-pressure wood chips to a pressurized digester tank, such as that used in the manufacture of Kraft pulp. HPF feeders are described in U.S. Patents 4,107,843, 6,120,646, 5,236,285, 6,468,006 and 6,616,384 and in published international patent applications WO 94/21855 and WO 99/42653.

HPF feeders typically have a rotor with four transverse passages that are filled and emptied with cellulosic and liquid material as the rotor rotates inside a shell. HPFs typically have a low pressure discharge orifice through which the lye separated from the cellulosic material suspension passes.

To prevent loss of cellulosic material, a screen grid typically covers the low pressure discharge orifice. Low pressure bleach passes through the screen grid to the low pressure discharge orifice and blocks the cellulosic material so that it does not exit through the low pressure discharge orifice. In conventional HPF, the screen grid has a narrow solid section in the center that is aligned with a dividing bar on the HPF cover. The central section of the grid-screen adjoins the dividing bar of the discharge orifice in the middle of the low-pressure discharge orifice of the HPF envelope and below the screen-grid. The dividing bar is a narrow support wall that extends through the center of the low pressure discharge orifice.

The dividing bar and the narrow solid grid-screen section are generally aligned with a central solid circumferential portion of the HPF rotor. This alignment minimizes the flow obstruction caused by the dividing bar and the narrow solid section. The alignment between the discharge holes in the rotor and the screen grid and the partition wall changes as the rotor moves a relatively short distance, for example, 5 inches (127 mm (mm)), axially with respect to the lining and cover of the HPF. The rotor moves periodically to compensate for wear on the rotor surfaces and the lining. Moving the rotor axially changes the alignment between the discharge holes in the rotor and the central solid portion of the screen grid and the partition wall. As the alignment changes, the central solid portion of the screen-grid and the partition wall can be misaligned from the center of the rotor and thus obstruct the flow of bleach that passes through the low-pressure discharge orifice of the HPF.

Conventional HPFs have double screen grilles with slots that do not extend continuously over the entire surface of the screen grid exposed to the ports in the rotor and the low pressure discharge hole in the cover. Because the groove region is not continuous, the screen grid has solid sections that obstruct the low pressure flow of bleach from the HPF. The rotor is clogged specifically near the discharge hole splitter bar and the motor side end of the shell. The dividing bar and the narrow solid section of the screen grid obstruct the flow of bleach through the discharge holes in the rotor and the low pressure discharge hole in the HPF cover. Obstruction of the bleach flow to the low pressure discharge orifice reduces the efficiency and capacity of the HPF.

US-A-5,236,285 describes a rotating high pressure feeder according to the preamble of Claim 1.

BRIEF DESCRIPTION OF THE INVENTION

An unobstructed flow of bleach into the low pressure discharge orifice would allow the bleach to flow more easily through and out of the rotor. Allowing bleach to flow through and out of the rotor without obstruction improves the flow of wood chips through the HPF and into the high pressure discharge orifice of the HPF. An unobstructed flow of bleach through the low pressure discharge orifice would reduce the pressure in the flow that passes through the rotor while the rotor is aligned with the low pressure inlet opening toward the HPF. An unobstructed flow of bleach through the low pressure discharge orifice would increase the amount of chips that fill the rotor as the low pressure chip and bleach suspension enters the HPF and the rotor.

There has been a need for a long time to improve the efficiency and capacity of HPFs. Obstructions to the flow of low pressure discharge orifice in an HPF tend to reduce the capacity and efficiency of an HPF. Increasing the capacity of HPF allows greater amounts of wood chips to flow through the HPF and to be pressed through said HPF. Reducing obstructions to the low pressure discharge orifice tends to increase the efficiency of the HPF by increasing the capacity of the HPF without requiring an increase in the power applied to drive the HPF.

In this context, the present invention provides a rotating high pressure feeder for processing cellulosic fibrous material according to Claim 1. Preferred optional features are listed in the dependent claims.

In the rotating high pressure feeder according to the present invention, the screen-grid slots have been enlarged to form a single, continuous and large area with grooves in the screen-grid that corresponds to the entire area of the discharge port of Low pressure and to the areas of the ports in the rotor. The cover portion for the coupling of the rotor motor side can be reduced in size, for example, by an inch (25 mm), to allow an expansion of the open area of the low pressure discharge hole in the cover and allow a surface of area with slots larger than the grid-screen. The center bar in the low pressure discharge orifice of the liner can be removed. The expanded discharge hole of the cover and the grooved surface of the screen-grid allow the flow of low-pressure liquid to increase through the discharge holes in the rotor with cavities and outside the HPF. The flow of fluid through the grooves helps to achieve greater grid-screen efficiency.

In addition, the discharge orifice divider bar in the low pressure discharge orifice is shortened to prevent it from touching the screen grid. A gap formed between the inner end of the dividing bar and the screen-grid allows liquid to flow through and out of the central region of the screen-grid.

Likewise, by increasing the slot opening width to between 8 millimeters (mm) and 25 mm in the screen grid and increasing the area of the groove region in the screen grid, the capacity and efficiency of the liquid flow through increases. of the grid-screen.

BRIEF DESCRIPTION OF THE DRAWINGS

Figures 1 and 2 are schematic views of a conventional high pressure feeder (HPF) in a feed system for a digester tank.

Figure 3 is a perspective view of a conventional high pressure feeder.

Figure 4 is a perspective view of the rotor, liner and screen-grid of the conventional high pressure feeder shown in Figures 1 to 3.

Figures 5A and 5B are cross-sectional views of a lower half of a conventional high pressure feeder.

Figures 6A and 6B are cross-sectional views of a lower half of a high pressure feeder having an expanded low pressure discharge port, an elongated screen-grid and a shortened dividing wall.

Figure 7 is a perspective view of a liner and screen-grid shown in Figures 6A and 6B.

Figure 8 is a graph of a screen area with slots exposed as a function of the axial position of the rotor on the HPF cover for a conventional screen-grid and for the elongated screen-grid.

DETAILED DESCRIPTION OF THE INVENTION

Figures 1 and 2 schematically illustrate the operation of a high pressure transfer device, which is also referred to as a high pressure feeder (HPF) 10. Since it is conventional, the HPF 10 is connected to a gutter of chip feed 11, in which vaporized wood chips (or other cellulosic material) are supplied from a vaporization tank 9; the suspended chips are mixed with liquid (bleach) from a liquid supply conduit 12. The feed channel 11 is connected to a first port (low pressure inlet port) 13 of an envelope (cover) 14 of the HPF 10 The housing also has a second port (high pressure inlet port) 15, a third port (low pressure discharge hole) 16, and a fourth port (high pressure discharge port) 17. These ports 13, 15 , 16 and 17 are arranged around deck 14 at intervals of approximately 90 degrees. A rotor with cavities 19 rotates (see direction of rotation 18) inside the shell 14.

The rotor 19 typically has four cavities 21, each of which forms a flow passage that extends through the rotor in a direction perpendicular to the axis of rotation of the rotor. The rotational axis is perpendicular to the plane of Figures 1 and 2. The rotor rotates continuously to alternately align the cavities with ports 1 and 3 (which are in vertical alignment) and then with ports 2 and 4 (which are in horizontal alignment ). Figure 1 shows a rotor cavity 21 aligned vertically with the first port and the third port, which form a low pressure passage to allow wood chips and bleach from the chip tube 11 to enter and fill the cavity 21 to through the low pressure inlet port (first port) 13 and so that the bleach flows simultaneously out of the low pressure discharge port (third port) 16.

Figure 2 shows the cavity 21 aligned horizontally with the high pressure inlet port (second port) 15 and a high pressure discharge port (fourth port) 17. During each rotation of a quarter of the rotor, the cavities 21 are aligned alternatively with the low pressure inlet and discharge port of the shell and then with the high pressure inlet and discharge port. When aligned with the low pressure inlet and discharge orifice 13, 16, a chip suspension fills the cavity 21 and liquid is withdrawn from the suspension through the discharge orifice port 16. As the cavity rotates with the rotor, the chips are trapped in the cavity until the cavity is aligned with the inlet port and the high pressure discharge hole 15, 17 at which point high pressure liquid flows through the inlet port 15 and exits chips and liquid to a high pressure conduit 22 connected to the high pressure discharge orifice 17.

A high pressure pump 20 or other source of high pressure liquid (bleach) is connected to the second port 15 (high pressure inlet port). As illustrated in Figure 2, the pump 20 provides high pressure liquid to the second port 15 which, when the cavity 21 is horizontal, abundantly washes the wood chips or other cellulosic fibrous material inside the cavity 21 causing them to exit high pressure through the fourth port 17 (high pressure discharge orifice) through the high pressure circulation conduit 22 associated with a continuous digester reservoir 23. The high pressure conduit 22 feeds the pressurized chips in suspension at a higher pressure at atmospheric towards an upper inlet orifice 24 of the digester tank 23. In the upper inlet orifice 24 a conventional solid and liquid separator is provided which returns part of the liquid through the conduit 25 which can direct part or all of the liquid into the inlet port towards the pump 20. The liquid in the ducts 22, 25 is typically white bleach and may include condensate steam and sometimes black bleach, and that can be complemented with the splicing bleach conduit 26. For non-Kraft situations, the liquid in lines 22, 25 could be water, solvent-making paste liquid, etc.

Connected to the third port 16 (low pressure discharge orifice), and offering suction in said port is a low pressure discharge conduit 27 connected to a low pressure pump 28, the pump 28 being in turn connected to the conduit12 for supply suspension liquid to the chip feed channel 11.

A conventional screen screen 29 is mounted inside the shell 14 in the third port 13. As shown in Figure 1, the screen screen 29 allows liquid to pass at low pressure, for example, atmospheric pressure (or slightly above the atmospheric pressure due to the chip tube) to the duct 27 under the influence of pump suction 28 and gravity. The screen grid prevents chips or other cellulosic fibrous material from passing through the third port 13. The screen grid ensures that the chips or other cellulosic fibrous material remain in the cavity 21 of the rotor 19 and fill it while the cavity is vertically aligned with the first and third ports.

Figure 3 is a perspective view of a conventional high pressure feeder (HPF) 10. Ports 13, 15, 16 and 17 are provided on the cover 14 of the HPF. Each port is generally rectangular in shape, but may have an adapted shape to accommodate the flow into and out of the rotor and into a conduit connected to the inlet hole. The elongated rectangular ports (see numbers 13, 17 in Figure 3) are aligned with the four rotor cavities 19. A dividing wall 30 is centered on each of the ports 13, 15, 16 and 17 and is preferably aligned between the rotor cavities to avoid obstructing the flow through the cavities. The dividing wall 30 is a structural support for the roof ports. An inner end of the partition wall 30 is adjacent to a shell liner 32 or an inner wall of the roof

14.

The rotor 19 is attached to the axes 34 coaxial to the axis of rotation of the rotor. The shafts are supported by bearings in the cover. A motor is coupled to one of the axes to rotationally drive the rotor. The shafts allow a limited axial adjustment of the rotor inside the cover.

An adjustment device (represented by the manual turning wheel 33) moves the axes and the rotor axially with respect to the cover. Typically, the rotor moves axially in the cover to adjust the space between the rotor and the inner lining or wall of the cover. The rotor and inner lining / wall of the cover may each narrow slightly along the length of the cylindrical shape. Because the rotor and the inner liner / wall narrow, moving the rotor axially changes the space between the rotor and the inner liner / wall. The space can be adjusted to compensate for rotor, lining and inner wall wear.

Figure 4 is a detailed view of the rotor 19, shell liner 32 and a conventional screen-grid 29. The rotor narrows from a first end 36 to the second end 38. The rotor rests on the liner and rotates thereon. . The liner 32 narrows correspondingly towards the rotor. The rotor 19 includes one or more (for example, four) diametrically through cavities 21.

Each of the cavities 21 forms a flow passage that extends through the rotor in a direction transverse to the rotational axis. Each cavity has ports 40, 42 that alternatively allow a flow into and out of the cavity. Each cavity 21 has a pair of ports 40 or 42 that are aligned along a flow passage that extends perpendicular to the rotor shaft.

Ports 40 on the left side of the rotor are provided for the pair of cavities 21 on the left side of the rotor. Ports 42 are provided in the rotor for the pair of cavities 21 on the right side of the rotor.

As the rotor rotates in the liner, the ports 40, 42 of the cavities move in and out of the alignment with the openings 46 in the liner. Each of the openings 46 in the lining corresponds to and is aligned with one of the ports 13, 15, 16 and 17 in the HPF. A central circumferential section 63 of the coating is conventionally solid. The central section 63 of the liner is aligned with the middle section of the screen-grid 60 and is generally aligned with the central circumferential section 62 of the rotor.

Conventional screen-grid 29 typically consists of two screen-screen sections 31 resting adjacent to each other in the low pressure discharge orifice of the cover. Each screen-grid section includes an integral metal body, for example, molten metal, having a frame 50 and a plurality of bars 52. The frame is defined by opposite sides 54 generally arranged parallel to the rotor axis, and opposite sides 56 arranged perpendicular to the rotor shaft. The bars 52 can be concave to adapt to the shape of the outer surface of the rotor and have a lower region along the midline 58.

Slots are formed between the bars and are parallel to the bars. The width of the grooves is typically around 8 millimeters (mm). The grooves are narrow enough to block the passage of wood chips and allow the passage of bleach out of the cavity 21.

A central portion 60 of the screen grid 29 is solid and has an outer surface that provides a contact with the partition wall 30 in the discharge port 30. The screen grid extends substantially along the length of the rotor. and the central portion 60 is generally aligned with a circumferential region 62 of the rotor between ports 40, 42 on the left and right sides of the rotor.

The thickness (TH) of the screen-grid can be narrowed from one end 56 to the other end 56. The narrowed shape adapts to the narrowed shape of the liner and rotor.

The screen grid 31 has a notch 100 that is supported by points 102 extending inwardly from an inner wall 75 of the low pressure discharge hole of the HPF 14 cover. The fixing screws 104 secure the screen screen 31 to tips 102 and cover.

Figures 5A and 5B are cross-sectional views of a lower half of a conventional high pressure feeder.

10. Figure 5A shows shaft 34 and rotor 19 extended to the left in the feeder housing. Figure 5B shows shaft 34 and rotor 19 extended to the right in the feeder housing.

The grid-screen 29 shown in Figures 5A and 5B is a conventional grid as shown in Figure

4. The grid rests on the cover 14 of the HPF above the low pressure discharge port (third port) 16. The central section 60 of the screen grid adjoins the inner end of the dividing wall 30.

The central section may have a groove or groove on the outer surface to receive the inner end of the dividing wall.

The central section 60 and inner end of the dividing wall 30 obstructs a portion of the low pressure discharge orifice 16 of the cover and the ports 40, 42 in the rotor. The degree of obstruction to flow through the low pressure discharge orifice 16 varies according to the axial position of the rotor in the cover. The central section 60 and the dividing wall 30 are generally aligned with the circumferential central section 62 of the rotor, especially when the rotor is back against the left side of the cover as shown in Figure 5A. The central section 60 and the dividing wall 30 are less aligned with the circumferential center 62 of the rotor when the rotor is axially forward towards the right side of the cover, as shown in Figure 5B.

Figures 6A and 6B show cross-sectional views of a lower half of a high pressure feeder (HPF) 70. Figure 6A shows shaft 34 and rotor 19 extended to the left in the HPF shell. Figure 6B shows shaft 34 and rotor 19 extended to the right in the HPF shell.

HPF 70 is similar in many ways to HPF 10. The differences between the two HPF 10, 70 include that HPF 70 has a screen-grid 72 with wide slots; the grooved region 108 of the screen-grid 72 is enlarged and is continuous along the length of the screen-grid to adapt to the shape of the entire area of the expanded low-pressure discharge orifice 16. In addition, the wall 74 of the low pressure discharge orifice 16 has been axially displaced outwardly to expand the open area of the low pressure discharge orifice. The end 76 of the partition wall 78 is separated from the screen grid 72 by a gap (G). Also, the central circumferential sections 62, 63 of the rotor and of the liner, respectively, can be narrowed to allow the ports 40, 42 of the rotor and the discharge holes 46 in the liner to expand. The center bar in the low pressure discharge orifice of the liner has been removed to open the flow area through the liner.

The dividing wall 78 in the low pressure discharge orifice is not in contact with the screen grid 72. A gap (G), for example, one to two inches (25 mm to 50 mm) between the end 76 of the dividing wall and the outer surface of the screen-grid 72 allows the liquid flowing out of the screen-grid to enter the discharge hole 16 and from there to pass over the end 76 of the partition wall. In view of the gap (G), the grooved region of the screen-grid extends through the middle region of the screen-grid. The screen grid 72 does not need to have a solid center section (or a solid region at the junction of the two screen-grid sections 31).

The inventors recognized that the end of the dividing wall does not need to be in contact with the screen grid. In addition, the inventors recognized that offering a gap (G) between the end of the dividing wall and the screen grid and offering grooves through the center of the screen grid would allow the liquid to flow through the center of the screen grid.

The end of the motor side of the cover can be reduced in length to effectively expand the open area of the low pressure discharge orifice 16. In addition, the inner wall 74 of the low pressure discharge orifice 16 can move relative to the wall corresponding 75 of a conventional HPF. For example, the wall 74 of the low pressure discharge orifice travels a distance (T) that may be about one inch (25 mm). The inventors recognized that moving the wall, for example, by changing the slope of the wall 74, allows a greater part of the grid 72 to pass a low pressure liquid flow in line with the opening 21 of the rotor.

Figure 7 is a perspective view of a screen grid 72 having bars 82 and slots 84 between the bars. Each of the slots can form a gap of about 10 mm to 25 mm. The liquid flows through the slots 84 and the chips are retained by the bars in the rotor cavity. The grooves and bars extend substantially along the entire length of the screen grid. The width of each of the bars can be greater, for example, from 10 mm to 25 mm, than the width of the grooves. A uniform set of grooves and parallel bars extends without interruption through the portion of the screen-grid corresponding to the opening in the low-pressure discharge orifice of the HPF. Because the assembly is uniform, there is no wide solid bar in the center of the screen-grid as with conventional screen-screens.

Figure 7 shows that the central circumferential bar in the low pressure discharge orifice of the liner 110 can be removed. Similarly, a solid central section is not necessary on the screen grid. The bars 82 can be concave to fit the cylindrical shape of the rotor. The length (L) of the grooved section of the screen-grid 72 substantially covers the total length of the open area of the low pressure discharge port 16 and the ports 42, 44 to the rotor. This length (L) is greater than that of conventional screen gratings, for example, about one inch, due to the increased length of the opening in the lining.

Figure 8 is a graph 90 showing the percentage of open screen based on the axial position of the rotor on a cover of an HPF. Curved line 92 represents the percentage of open screen for conventional HPF 10 and shows the change in this percentage as the rotor moves axially in the cover. The curved line 94 represents the percentage of open screen for the screen-grid 72 in the HPF 70 and shows that the opening percentage remains very high, for example, effectively, 100 percent, regardless of the axial position of the rotor.

Specifically, the curved line 92 represents a conventional HPF 10 having a screen-grid 29 with a nominal slot size of 8 mm, a dividing bar that borders a central region of the screen-grid, and an elongated end of the side of the cover motor 14. As shown with curved line 92, when the rotor is positioned on the cover as shown in Figure 5A (which is the rotor position typically used at the beginning of the life of the HPF), the efficiency of the grid-screen flow is just above 75% due to the number of unobstructed slots in the screen-grid and the reduced width of the slots. As the rotor wears out, it moves axially towards the center of the cover. The advance of the rotor results in the availability of more screen slots (due to the better alignment between the central section of the screen-grid and the center of the rotor) so that the flow of liquid increases through the grid- screen and efficiency increases to almost 95 percent. As the rotor continues to wear and moves axially toward the end of the motor side of the cover, the screen slots become clogged again and the efficiency is reduced to about 85 percent.

The high and uniform efficiency represented by the straight line 94 is due to the unobstructed grooves in the screen grid regardless of the axial position of the rotor, the widest slots in the screen grid, a single and longer screen grid (due to the length added to the screen grid by increasing the length of the lining opening), and a shortened discharge hole dividing bar that does not block a portion of the screen screen.

Some of the features and advantages offered by HPF 70 include:

A- Increased efficiency of liquid flow through the screen grid during the life of the rotor.

B- Groove width in the screen grid between 10 and 25 mm that is larger than that of conventional grooves.

C- A shorter discharge orifice dividing bar that does not come into contact with the screen-grid and, thus, allows a single and larger screen-grid with grooves facing the bar that is unobstructed by the bar.

D- Longer length of openings in the lining to expand the low pressure discharge hole in the cover and allow a longer screen-grid with an area with larger grooves.

While the invention has been described in relation to what is currently considered the most practical embodiment and

10 preferred, it is to be understood that the invention should not be limited to the described embodiment but, on the contrary, is intended to encompass various modifications and equivalent provisions included within the spirit and scope of the appended claims.

REFERENCES CITED IN THE DESCRIPTIVE MEMORY

This list of references cited by the applicant is for the convenience of the reader only. It is not part of the European patent document. Even when great care was taken to comply with the references, 5 errors or omissions cannot be excluded and the EPO declines all responsibility in this regard.

Patent documents cited in the specification

• US 61169378 A [0001] • US 6468006 A [0003] 10 • US 4107843 A [0003] • US 6616384 A [0003]

•

US 6120646 A [0003] • WO 9421855 A [0003]

•

US 5236285 A [0003] [0008] • WO 9942653 A [0003]

Claims (10)

1. A rotating high pressure feeder (70) for processing cellulosic fibrous material, comprising: a rotor with cavities (19) containing a plurality of cavities through which flow passes (21), said rotor (19) being able to rotate about a rotation axis and said cavities (21) having opposite end openings that work both as inlet and discharge holes according to an angular position of the rotor (19) within the device, and said cavities (21) are provided in at least a first and a second set; enclosing a casing (14) said rotor (19), said casing (14) having a low pressure inlet port (13) aligned with a low pressure discharge orifice port (16), and an orifice port of high pressure inlet (15) aligned with a high pressure discharge orifice port (17), in which said ports are arranged to be registered with the inlet holes and discharge ports of said cavities through which flow passes (21) and said rotor (19) mounted on said housing (14) to rotate with respect to said ports around said given axes of rotation, and a screen grid (72) supported on or adjacent to the low pressure discharge orifice port (16), in which the screen grid (72) has a set of screen slots (84) and bars (82), in which a regular pattern of the grooves (84) and bars (82) extends through the entire low pressure discharge port port (16), characterized in that a dividing wall (78) crosses the low pressure discharge orifice port (16), and there is a gap (G) between the inner end (76) of the partition wall (78) and the screen grid (72), in which the liquid flowing through the slots (84) passes through the gap (G).

2.

The rotating high pressure feeder (70) in Claim 1, wherein the gap (G) is in the order of one to two inches between the outer surface of the screen grid (72) and the inner edge (76) of the dividing wall (78).

3.

The rotating high pressure feeder (70) in Claim 1 or 2, wherein the grooves (84) and the bars (82) are perpendicular to the rotor shaft (19).

Four.

The rotating high pressure feeder (70) in Claim 3, wherein the partition wall (78) is perpendicular to the axis of the rotor (19).

5.

The rotating high pressure feeder (70) in any of the preceding claims, wherein the low pressure discharge orifice port (16) forms an open area of the shell (14), and the set of screen slots ( 84) and bars (82) extends at least over the entire open area.

6.

The rotating high pressure feeder (70) in any of the preceding claims, wherein the pattern is a uniform pattern of grooves (84) and bars (82) that extends without interruption through an open region of the orifice port Low pressure discharge (16).

7.

The rotating high pressure feeder (70) in any of the preceding claims, wherein each slot has a width ranging from 10 mm to 25 mm.

8.

The rotating high pressure feeder (70) in Claim 7, wherein each bar is wider than each slot.

9.

The rotating high pressure feeder (70) as mentioned in any of the preceding claims, further comprising a cylindrical liner whose shape narrows in the shell (14) and enclosing the rotor (19), in which the The lining has a unique uninterrupted low pressure discharge orifice aligned with the screen grid (72).

10.

The rotating high pressure feeder (70) as mentioned in any of the preceding claims, wherein:

The rotor (19) comprises at least one cavity comprising a conduit that extends through the rotor (19) in a direction perpendicular to the axis and having end openings at opposite ends of the cavity, in which each of said End openings of each cavity works both as an inlet and discharge hole according to an angular position of the rotor (19) within the shell (14); the low pressure inlet port (13) is adapted to receive a low pressure suspension of the cellulosic fibrous material and a liquid, and the low pressure discharge port port (16) is aligned vertically with the orifice port low pressure inlet (13) and adapted to discharge low pressure liquid extracted from the low pressure suspension that passes through the low pressure inlet port, and the high pressure inlet port (15) is adapted to receive a high pressure liquid fluid, and the high pressure discharge port (17) is aligned horizontally with the high pressure inlet port ( 15) and adapted to discharge at high pressure the cellulosic fibrous material that passed through the low pressure inlet port.